Electric switch



Nov. 22, 1960 M. COLETTE 2,961,504

ELECTRIC SWITCH Original Filed March 16, 1956 uvvsmon MICHAEL COLETTE By F419. 6 Qy MM A770 NEW United States Patent ELECTRIC SWITCH Michael Colette, Detroit, Mich, assignor to William G. Mason and Alfred L. May, both of Detroit, Mich.

Original application Mar. 16, 1956, Ser. No. 571,993,

now Patent No. 2,868,918, dated Jan. 13, 1959. Divided and this application Nov. 12, 1958, Ser. No. 773,334

3 Claims. (Cl. 200-67) This invention relates to sump pumps and to an improved electric switch, particularly, but not exclusively, advantageous in use with such pumps. The present application is a division of my co-pending application, Serial No. 571,993, filed March 16, 1956, for Electric Switch now Patent No. 2,868,918, Jan. 13, 1959.

Considerable difliculties have been experienced with the use of electric switches for sump pumps. Such pumps are usually installed in damp places for removing seepage water. With the air around the pump being very damp and with moisture precipitating within the switch, difficulties have been experienced in producing a switch properly insulated for use under such conditions and with its insulating material not subject to deterioration under condition of dampness. With such switches often going out of order, their frequent inspection and replacement is necessary. Very frequently such work has to be done in dark places with little or no illumination, such as in a dark corner of a basement, using a flashlight which has to be held in one hand, making it difiicult to do the work requiring the use of both hands. In spite of such a situation, such difliculties and disadvantages have been considered by those skilled in the art as being unavoidable and resulting from the nature of the use of such switches rather than from their construction. In addition, considerable difliculties have been experienced in calibration of such switches to ensure their proper actuation by sump pump floats. One of the objects of the present invention is to provide an improved electric switch device whereby the above difi'iculties and disadvantages are overcome and largely eliminated and a simple, reliable electric switch particularly advantageous in use on sump pumps and in similar installations is produced.

Another object of the present invention is to provide an improved electric switch device which is exceedingly simple and compact and can be easily opened for inspection with its electrical part being easily replaceable as a unit without the necessity of removing the'entire switch.

A further object of the present invention is to provide an electric switch of the foregoing nature possessing superior insulation characteristics and which need not be calibrated for its application in a sump pump.

An added object of the present invention is to provide an improved electric switch of the nature specified above, which is simple in construction, dependable in operation,

is relatively inexpensive to manufacture and easy to repair.

Further objects and advantages of this invention will be apparent from the following description and appended claims, reference being had to the accompanying drawings forming a part of this application, wherein like reference characters designate corresponding parts in the "ice separately, said view being partly in section and taken in the direction of the arrows from the section plane 3-3 of Fig. 2. e

Fig. 4 is a sectional view taken in the direction of the arrows on the section plane passing through the line 44 of Fig. 3, the operative parts of the switch being shown in their closed position.

Fig. 5 is a view similar in part to Fig. 4 but showing the parts of the switch in their open position.

Fig. 6 is an exploded view showing the switch actuating iece. p Fig. 7 is a perspectiveview showing the top portion of the switch-actuating piece sub-assembly;

Fig. 8 is a view showing the switch-actuating piece made of insulating nylon material and of one piece or integral construction.

It is to be understood that the invention is not limited in its application to the details of construction and arrangement of parts illustrated in the accompanying drawings, s nce the invention is capable of other embodiments and of being practiced or carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein is for the purpose of description and not of limitation.

In accordance with the invention, I provide an improved electric switch device of superior insulating characteristics, with said switch including a snap action mechanism and having its electrical part removable from its casing as a unit for replacement or repair.

Referring specifically to the drawing, Fig. 1 illustrates a sump pump including a tubular column 10 mounted on a base 11 and having an intake and with a screen 12. At the top of the column 10 there is provided an electric motor-and-pump aggregate generally designated with the numeral 13. An electric cord 14 is electrically connected to the electric motor. In such connection there is operative'y interposed an electric switch generally designated by the numeral 15. A float 16 actuated by the level of the water at the lower portion of the column 10 is adapted to slide on the rod 17 between the adjustable collars 18 and 19 fixed in desired places on the rod 17. The upper end of the rod 17 is hingedly connected to the switch actuating piece 20.

The upper collar 19 is adjustable to a desired height to determine the level at which the pump begins operating. The weight of the rod 17 and of the float is suflicient to pull the piece 20 and to open the switch as shown in Fig. 5. Therefore, normally the switch remains open. However, should the level of the water around the lower part of column 10 rise to the level 21, the float 16 will press on the collar 19 and will push the rod 17 up together with the piece 20, thus bringing the operative parts of the switch into the relative positions shown in Fig. 4 and thus closing the switch. Thereupon, the pump will begin operating to pump the water out. As the water level drops, the float 16 reaches the collar 18, whereupon the weight of the rod 17 and of the float 16 acting on the collar 18 and pulling on the piece 20 through the rod 17 again opens the switch to stop the motor and the pump.

The switch 15 comprises a two-piece casing, including the lower portion having a bottom 30 provided with an opening 31 for passage of the switch actuating piece 20, side walls 32 and 33 and a back wall 34 provided with aperture 35 for passage ,of the electric wires and holes 34a for passage of screws or similar connectors for securing the switch in place on the motor-and-pump aggregate. Thus, the top and the front of the lower portion of the casing are open as can be'best appreciated by examination of Fig. 1. The upper portion or the cover of the casing comprises a top 36 and a front wall 37 provided with flanges going over side walls 32 and 33, see Fig. 1. A rear flange 38 is adapted to go over the upper edge of the teams back wall 34, while the front wall 37 is also provided with a lower flange 39 going over the front edge of the bottom 30. An extension 40 is provided to enable easy removal of the cover.

Lugs 41 and 42 are stamped out from the material of the back wall 34 and are adapted to support the entire switch assembly connected to said lugs with the aid of screws 43 and 44.

The switch assembly comprises a shelf 50 made of an insulating material and having terminals 51 and 52 provided on its top, for receiving electric wires. Brackets 53 and 54 are provided on the underside of the shelf 50 and are electrically connected through the terminal screws 55 and 56 with the terminals 51 and 52, respectively.

It will now be understood that if brackets 53 and 54 are electrically connected together, the terminals 51 and 52 will also be connected and electric current will flow through the switch. Means are provided to connect and disconnect electrically said terminals 51 and 52. Said means are exemplified by a copper spring 57 having one of its ends riveted or otherwise secured to the bracket 54 as at 53, and its other end carrying a contact point 59 adapted to contact and to be separated from the point 60 provided on the bracket 53. It will now be understood that when points 59 and 60 are in contact as shown in Fig. 4, the switch is closed. If points 59 and 60 are separated as shown in Fig. 5, the switch is open.

A snap action mechanism is provided to move the switch spring 57 into its circuit breaking and circuit closing positions. Said mechanism comprises a leaf spring bow 61 having holes through its ends through which prongs 57a of the spring 57 and prongs 62a of the spring 62 pass.

The spring 62 is shaped to exert constant pressure on the top of the switch actuating piece 20 and to be in constant mechanical contact therewith.

A compression coil spring 63 is provided on the piece 20, which spring is compressed between the lower portion of the bracket 64 and the cross head 65 carried by the piece 20. The piece 20 is provided with shoulders 20a bearing on said cross head 65. The piece 20 may be of articulated construction as shown in Fig. 6 and comprises a metal piece 20c and an insulating piece 20d, thus preventing the possibility of flow of current through the piece 20 to the ground.

It will now be seen with reference to Figs. 4 and that as the piece 20 moves downward from its position shown in Fig. 4, the bow piece 61 will be deflected to bring its ends closer together. This condition will continue for a short distance of movement of the end of the spring 6 2, whereupon the resiliency of the piece 60 will cause it to snap into the position shown in Fig. 5, moving the piece 57 to separate the contact points 59 and 60. Movement of the piece 20 upward will reverse this movement but also with a snap action. By the provision of the snap action mechanism described above, a greater distance of separation between points 59 and 60 and speedier separation thereof preventing sparking is attained.

The piece 20 as can be understood from the above, must possess both electric insulation properties and mechanical strength. It is for this reason that it may be made partly of metal and partly of insulating material. I also found it very advantageous to make such piece out of nylon material which possesses both electric insulation properties and greater mechanical strength. Such piece is made of integral or one-piece construction as shown in Fig. 8 wherein said piece is designated by the numeral 70.

By using a stronger spring instead of spring 63, the switch may be used as a displacement weight type switch, such as in cases where instead of a rod such as 17, a wire with two weights is used.

By virtue of the construction disclosed above, the objects of the present invention and numerous additional advantages are attained.

I claim:

1. A push-pull snap action type switch comprising an insulating base shelf; three spaced apart brackets on the underside of said base shelf and secured thereto transversely of the longitudinal centerline of said base, one of said brackets fixedly secured to said insulating base; the second and intermediate of said brackets attached to said base and bridging outwardly from said base and providing an electrical contact selectively opened or closed, the third of said brackets also bridging outwardly from said base providing a cage structure; a fiat leaf spring secured at one end by said first bracket to said base and extending longitudinally of said base, through said second bracket and selectively movable within said bracket toward and away from said base; a second leaf secured to said base at the opposite end of said base from said first leaf and through said third bracket and being movable in said bracket toward and away from said base; a bow spring intermediate said leaves and pivotally engaged with the ends of each of said leaves; spring loaded actuating means caged in said third bracket and biased against second leaf intermediate the ends thereof; and electrical leads connected to said first leaf at said first bracket and to said second bracket for selective opening and closing relationship in accord with the movement of said first leaf into and out of contact with said second bracket.

2. A push-pull snap action type switch comprising an insulating base shelf having openings therethrough for mounting and having a transverse slot therethrough located proximate to the longitudinal centerline of said base; three spaced apart brackets in straddle relationship transversely and symmetrically postioned across the longitudinal centerline of said base, the first of said brackets fixedly secured to said insulating base, the second and intermediate of said brackets attached to said base in parallel relationship to said first bracket and bridging outwardly from said base; the third of said brackets parallel to the first and second said brackets and bridging outwardly from said base providing a cage structure; an electrical lead contacting said first bracket; a fiat leaf spring secured by said first bracket to said base and in contact with said lead and extending longitudinally of said base through said second bracket and movable within said bracket toward and away from said base; a bow spring element hinged to the end of said first leaf spring and pivotal thereon, one extreme of bias travel extending through the said transverse slot in said base; and a second leaf spring secured to said base on the centerline thereof and extending parallel to said first leaf spring and pivotally secured at its inner end to said bow spring, said second leaf extending through the third of said brackets and being movable toward and away from said base; a spring loaded and insulated actuating plunger through said bracket and caged thereby in contacting control against said second leaf spring; whereby selected movement of said plunger is followed by said second leaf.

3. In the combination switch as expressed in claim 2 wherein the bow spring element difines two spaced apart symmetrically positioned openings therethrough at each end of said bow; the first leaf spring having prongs at one end thereof matingly insertable in said openings defined by said bow spring; and the second leaf spring having identical prongs extending for insertion in the other openings in the opposite end of said how spring.

References Cited in the file of this patent UNITED STATES PATENTS ,863 Sargent et al Dec. 29, 1925 ,7 0, 69 Hayes Mar. 11, 1930 9,789 Benander Feb. 24, 1953 90,866 Cherry Apr. 30, 1957 

